1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), and more particularly, to an LCD capable of driving pixels and realizing dot inversion without using bridge lines.
2. Description of Prior Art
With a rapid development of monitor types, novel and colorful monitors with high resolution, e.g., liquid crystal displays (LCDs), are indispensable components used in various electronic products such as monitors for notebook computers, personal digital assistants (PDAs), digital cameras, and projectors. The demand for the novelty and colorful monitors has increased tremendously.
Refer to FIG. 1, which shows a schematic diagram of a traditional LCD 10 applying a half source driver (HSD) technology. The LCD 10 comprises a pixel matrix 12, a gate driver 14, and a source driver 16. The pixel matrix 12 comprises a plurality of subpixels standing for three primary colors—red (R), green (G), and blue (B). For example, a pixel matrix 12 with a resolution of 1024×768 comprises 1024×768×3 subpixels. The gate driver 14 outputs gate signals through gate lines G1-Gn to cause pixels in each row to be turned on orderly. Meanwhile, the source driver 16 outputs a corresponding data signal to pixels in each row through data lines D1-Dm, so that the pixels in each row can obtain their individually required display voltage at full charge to show various gray levels. All of the pixels of the pixel matrix 12 complete being charged based on this sequence. Afterwards, the pixels in the first row start to be charged again.
In a traditional gate driving technology, each of the subpixels is electrically connected to a data line and a gate line. But currently, the traditional gate driving technology is replaced by a 2G-hD technology in applications because a source driver is more expensive than a gate driver. Technically speaking, the 2G-hD technology is that a subpixel requires two gate lines and one half data line. But the 2G-hD technology needs to use bridge lines to implement dot inversion. Take transistors T1-T4 which the pixels correspond to for example. Due to the intersection of bridge lines, parasitic capacitances are induced or even other parasitic effects occur in the vicinity of the transistors T2 and T3, as shown in FIG. 1.
On the other hand, a user may view different gray levels images on a traditional LCD monitor depending on his/her viewing angles. For instance, a user will see whiter gray level images on the LCD monitor if he/she views images at a slanted angle (e.g., 60 degrees) compared with viewing the images at a right angle (i.e., 90 degrees). That different gray levels are shown owing to different viewing angles is called a color shift phenomenon. The color shift phenomenon is more obvious when watching a large-sized LCD. A common used method for improving the impact of the color shift phenomenon is that each of the pixels is divided into two subpixels. One of the subpixels shows higher (brighter) gray level, and the other shows lower (darker) gray level. When a user sees a superposition of colors of the two subpixels at different angles, he/she will not have obvious visual distinctions. Traditionally, there are two methods for controlling the two subpixels to display brightness and darkness, respectively. One method is adopting capacitor coupling, and the other method is to adjust signals from common voltage VCOM, gate lines and on data lines. A disadvantage of the former method is that the voltage difference between the two subpixels is constant, so color shift cannot be effectively lowered. A disadvantage of the latter method is that the method needs to adopt specially designed a common voltage generator, a gate driver, and a source driver, and increasing extra cost. Therefore, it is required for the industry to control the two subpixels with ideal voltage to precisely show the subpixel in brightness and the subpixel in darkness, to reduce the effect of parasitic capacitances induced by bridge lines, and to implement dot inversion in pixel arrangements.